Rizwan Syed

An International Survey of Hospital Practice in the Imaging of Acute Scaphoid Trauma

OBJECTIVE Scaphoid fractures are relatively common. If not treated promptly there may be risk of long-term disability. However, unnecessary wrist immobilization is inconvenient and may hinder professional activities. Therefore, early accurate diagnosis is essential. Currently, the American College of Radiology deems MRI and radiographs as the most appropriate investigations in imaging acute scaphoid trauma. Our objective was to assess scaphoid imaging protocols. MATERIALS AND METHODS To assess scaphoid imaging protocols, an international survey of imaging practice was performed. Two hundred hospitals worldwide were sent a survey regarding their scaphoid trauma imaging protocols. Only replies from hospitals that had full CT, MRI, and scintigraphy facilities were accepted. RESULTS Data were obtained from 105 hospitals, of which 23 had fixed protocols. The number of scaphoid radiographic views varied from two to six. Before second-line investigations were initiated, repeat radiographs were usually performed in 76 of the 105 hospitals. In 29 hospitals, other imaging techniques were used without further radiography. The usual second-line investigation was MRI in 31/105, CT in 19/105, and scintigraphy in 14/105. Further protocols included CT or MRI in 10/105, CT or scintigraphy in 6/105, scintigraphy or MRI in 6/105, CT then MRI (if CT was negative) in 1/105, both CT and scintigraphy in 1/105, and scintigraphy then CT (if positive) in 1/105. There was equal preference among MRI, CT, and scintigraphy in 10/105 centers, and clinical examination and radiographs were used alone in 6/105. CONCLUSION The survey reveals marked inconsistency in the imaging of acute scaphoid injury. Although other factors may have played a role, limited scientific evidence regarding the ideal imaging in acute scaphoid trauma may be the root of this inconsistency.

18F-fluoroethylcholine (18F-Cho) PET/MRI functional parameters in pediatric astrocytic brain tumors.

Purpose To examine the feasibility of simultaneous acquisition of 18F-fluoroethylcholine (18F-choline) PET and functional MRI (standardized uptake value [SUV]max/mean and apparent diffusion coefficient [ADC]mean), using a hybrid PET/MRI scanner, for diagnosis and response assessment in a cohort of children with astrocytic brain tumors. Methods 18F-choline PET/MRI scans were performed in 12 patients with proven astrocytic tumors. Eight patients simultaneously underwent 18F-choline PET/MR follow-up scans after treatment. Uptake in the lesion above the normal brain activity was considered indicative of a positive scan. Maximum and mean SUVs (SUVmax and SUVmean) and mean ADC (ADCmean) of the whole tumor region of interest were assessed. Lesion size and contrast enhancement were recorded. For all tumors, the association between ADCmean and SUVmean/SUVmax values were assessed using the Spearman correlation coefficient. Results At baseline, the areas of 18F-choline uptake matched areas of contrast enhancement and restricted diffusion. There was a negative correlation trend between SUVmax and ADCmean and a positive correlation trend between SUVmax and tumor size. There was concordance between reduction in tumor size and reductions in SUVmax and SUVmean in 4 children, in three of whom ADCmean values were increased. In 2 patients, tumor size remained stable whereas SUVmax and SUVmean values were increased with reduction in the ADCmean values. Additionally, in 2 children, cross-sectional MRI showed an increase both in tumor size and SUVmax but a reduction in ADC values. Conclusions Simultaneous 18F-choline PET/MRI is a promising and reliable imaging tool for children with astrocytic tumors, as it permits monitoring of morphological and metabolic response and changes during therapy.

18F-fluorodeoxyglucose positron emission tomography/computed tomography in diagnosis of post-transplant lymphoproliferative disorder

Abstract The aim of the present study was to investigate the role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in the diagnosis of post-transplant lymphoproliferative disorder (PTLD), a serious complication of solid organ and bone marrow transplant. Between January 2004 and January 2012, 40 patients (22 males; median age 52 ± 17.4 years, range 11–77 years) underwent 18F-FDG PET/CT scans in our department for diagnostic evaluation of PTLD. Twenty-three (57.5%) patients had negative 18F-FDG PET/CT and 17 (42.5%) had a positive examination. In five patients PET/CT revealed extranodal disease (adrenal, pleural, spleen, liver, lung, esophagus and bone involvement). On the basis of our results, 18F-FDG PET/CT had a sensitivity of 88.2% (95% confidence interval [CI] 0.62–0.98), a specificity of 91.3% (CI 0.70–0.98), a positive predictive value of 88.2% (CI 0.62–0.98) and a negative predictive value of 91.3% (CI 0.70–0.98). The diagnostic performance of CT in patient-based analysis was: a sensitivity of 87.5% (CI 0.60–0.97), a specificity of 88.8% (CI 0.64-0.98), a positive predictive value of 87.5% (CI 0.60–0.97) and a negative predictive value of 88.8% (CI 0.64–0.98). PET/CT in five cases revealed more findings than CT, upstaging the disease, and revealed three extranodal findings, not visualized in conventional imaging. 18F-FDG PET/CT plays a significant role in the setting of PTLD diagnosis, demonstrating its high accuracy in detecting PTLD.

Painful knee prosthesis: can we help with bone SPECT/CT?

ObjectivesThe aim of the study was to evaluate the value of single-photon emission computerized tomography/computed tomography (SPECT/CT) in the clinical assessment of painful knee prostheses. Materials and methodsBetween 2009 and 2011 we identified 105 patients who had undergone 99mTc-hydroxydiphosphonate SPECT/CT for painful knee prosthesis. Complete follow-up data were available for 69 patients (50 women and 19 men; mean age, 71 years) with painful knee prostheses (59 total, nine unicompartmental, one patellofemoral) and clinical suspicion of infection or loosening. The imaging test report in conjunction with the clinical data from the patient’s notes was used to gauge how useful the test had been in terms of patient management. ResultsSPECT/CT confirmed the suspected clinical diagnosis of loosening in nine patients (13%) and of infection in two (2.9%) and identified other causes in 43 patients (62.3%). In 85.5% of patients, SPECT/CT was clinically useful (both positive and negative results), whereas in 14.5% it had no clinical impact on patient management. Revision surgery was performed in 24/69 (34.8%) patients and confirmed the SPECT/CT diagnosis in 21 patients (seven loosening, one infection, two subchondral fractures, two postoperative inflammation and nine patellofemoral osteoarthritis). ConclusionSPECT/CT is a useful tool for the evaluation of painful knee prosthesis in 85.5% of cases and helps in confirming mechanical loosening and in excluding other causes such as infection and patellofemoral osteoarthritis.

Adolescent With 68Ga DOTATATE-Avid Vertebral Hemangioma Mimicking Metastasis in PET Imaging.

⁶⁸Ga DOTATATE PET/CT is a well-established method in the diagnostic workup of neuroendocrine tumors. We report the case of a 15-year-old adolescent boy with histologically proven appendiceal carcinoid tumor referred for ⁶⁸Ga DOTATATE PET/CT to identify residual or metastatic disease. PET images showed increased tracer uptake in the body of T4 vertebra. This uptake could be misdiagnosed for bone metastasis, but CT characteristic appearance was in keeping with vertebral hemangioma. Both bone metastasis in carcinoid tumor and bone hemangiomas in adolescents are rare conditions, but the combined metabolic and morphological information on PET/CT can lead to the correct diagnosis.

Combined F-18 FDG positron emission tomography/computed tomography in the diagnosis of colonic polyps the potential and limitations of the technique

We present a case of a 66-year-old man who was diagnosed with a 16 X 10-mm cecal adenoma found incidentally on a combined F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) examination performed for lung cancer staging. Another 5-mm diameter colonic adenoma of identical histologic grade was identified at surgery, but was not visible (even retrospectively) on the PET/CT images. This case illustrates the potential of FDG PET/CT to identify colonic polyps greater than 1 cm, but also the inability of FDG PET/CT to detect subcentimeter premalignant polyps. This may limit its potential in diagnosis and screening.

Computed Tomography in Management of Patients with Non-Localizing Headache

OBJECTIVE To assess the usefulness of a computed tomography scan in patients with non-localized headache. METHODS One-hundred and forty-two patients with non-localized headache were included in a retrospective study after reviewing the medical records of 896 patients at the Radiology Department, Sultan Qaboos University Hospital. Patients with neurological deficits, head injury, previous intracranial intervention, or malignancy were excluded. Radiological findings of all patients were reviewed and results were divided into 3 groups: 1) no intracranial abnormality; 2) with clinically significant intracranial abnormality; and 3) positive without clinical significance or with extracranial abnormality. All patient history records were reviewed for a period of six months following their initial computed tomography scan to assess their clinical outcomes. The cost of computed tomography examination and patient radiation dose were calculated. RESULTS Of the 142 patients, 64% were females and 36% males (7% pediatric) with an age range of 4-87 years (mean: 36.2 years). Among the patients, 70% demonstrated negative computed tomography findings (grade 1), only 4% showed clinically significant findings (grade 2), and 26% demonstrated incidental positive findings with no clinical significance (grade 3). The average cost of computed tomography head examination was approximately 60 Omani Riyal (

How often do patients undergo repeat PET or PET/CT examinations? Experience from a UK institution.

156). The clinically significant positive cases were fewer than expected. The average estimated radiation dose for these patients was calculated and found to be around 5 times the radiation from computed tomography of the sinuses (approximately 1.84 mSv). CONCLUSION Computed tomography head imaging in patients with non-localized headache has a low likelihood for any significant intracranial lesion. Therefore, it is essential to develop local standard operating procedures to promote better utilization of this type of imaging service.

Spectrum of metastatic and nonmetastatic skeletal findings with dual-phase 18F-FECH PET/CT in patients with biochemical relapse of prostate cancer

Background and aimAccording to the report of the Intercollegiate Standing Committee on Nuclear Medicine, the UK requires 40–60 positron emission tomography (PET) machines in the next decade (Intercollegiate Standing Committee on Nuclear Medicine). Positron Emission Tomography: a Strategy for Provision in the UK. London: Royal College of Physicians of London; 2003, pp. 1–9). This figure is based mainly on patients receiving only one examination and restricting the clinical indication to three primary diagnoses. The aim of this study was to assess the appropriateness of this figure and the assumptions made in the Intercollegiate report on UK PET provision. MethodsWe examined retrospectively our institutions entire PET and PET/computed tomography (CT) database, which spans 4 years and 9 months. We recorded the number of patients who received repeat examinations. ResultsReports were available for 3354 PET/CT or PET-only studies; 418 of 2268 patients (18.4%) received at least one repeat PET/CT examination. The three main indications for PET examination in the Intercollegiate report only accounted for approximately 60% of the examinations undertaken. ConclusionOur records suggest that basing the UKs future PET provision on a single examination and on three clinical indications only is no longer realistic.

68Ga-DOTATATE PET/MR Imaging of Urinary Bladder Paraganglioma.

Introduction The aim of this study was to evaluate the spectrum of skeletal findings on dual-phase fluorine-18-fluoroethylcholine (18F-FECH) PET/CT performed during the work-up of patients referred for suspected prostate cancer relapse. Materials and methods Three hundred 18F-FECH PET/CT scans were evaluated prospectively. The low-dose CT features of all cases were categorized as isodense, sclerotic, lytic or mixed lytic/sclerotic and maximum standardized uptake value (SUVmax) values were calculated. Findings on 18F-FECH PET/CT were correlated with Technetium-99m-methylene diphosphonate planar bone scans and serum prostate-specific antigen. Results Patient age range was 50–90 years (median 71 years) and prostate-specific antigen values were in the range 0.04–372 ng/ml (Roche Modular method). Seventy-two lesions were detected on 18F-FECH PET/CT in 45 patients, including 31 (43%) in the pelvis, 17 (23%) in the spine (cervical 3, thoracic 8 and lumbar spine 6) and 10 (13%) in the ribs. Evaluation of low-dose CT in combination with PET helped to characterize benign findings in 21 (29%) lesions. The SUVmax for all except one benign lesion ranged from 0.49 to 2.15. In 51 (71%) lesions because of metastatic disease, SUVmax was 0.6–11.6 for those classified as sclerotic on low-dose CT, 0.7–8.58 for lytic lesions, 1.1–7.65 for isodense lesions and 1.27–3.53 for mixed lytic/sclerotic lesions. Of the 56 18F-FECH-avid lesions, 21 lesions showed avidity on bone scan [3 (23%) of the 13 isodense lesions, 14 (40%) of the 35 sclerotic lesions, 2 (50%) of the lytic lesions and 2 (50%) of the mixed sclerotic/lytic lesions]. Conclusion 18F-FECH PET/CT identified bone lesions in 15% of patients with suspected prostate cancer relapse. SUVmax in isolation cannot be used to characterize these lesions as benign or malignant. Minimal overlap of benign and malignant lesions was observed above SUVmax of 2.5. Low-dose CT of PET/CT is a useful tool to aid characterization.